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udp/dns/dnshdr.cpp@35:93c39d260a83, 2017-09-22 (annotated)

Committer:
andrewboyson
Date:
Fri Sep 22 13:55:56 2017 +0000
Revision:
35:93c39d260a83
Parent:
33:714a0345e59b
Child:
37:793b39683406
Added name resolution and address resolution

Who changed what in which revision?

UserRevisionLine numberNew contents of line
andrewboyson 13:9cd54f7db57a 1 #include "mbed.h"
andrewboyson 13:9cd54f7db57a 2 #include "dns.h"
andrewboyson 13:9cd54f7db57a 3 #include "net.h"
andrewboyson 13:9cd54f7db57a 4 #include "log.h"
andrewboyson 14:e75a59c1123d 5 #include "net.h"
andrewboyson 14:e75a59c1123d 6 #include "eth.h"
andrewboyson 14:e75a59c1123d 7 #include "ip4.h"
andrewboyson 14:e75a59c1123d 8 #include "ip6.h"
andrewboyson 14:e75a59c1123d 9 #include "udp.h"
andrewboyson 13:9cd54f7db57a 10
andrewboyson 13:9cd54f7db57a 11 #define HEADER_LENGTH 12
andrewboyson 13:9cd54f7db57a 12
andrewboyson 13:9cd54f7db57a 13 __packed struct header
andrewboyson 13:9cd54f7db57a 14 {
andrewboyson 13:9cd54f7db57a 15 uint16_t id;
andrewboyson 13:9cd54f7db57a 16 uint8_t uflags;
andrewboyson 13:9cd54f7db57a 17 uint8_t lflags;
andrewboyson 13:9cd54f7db57a 18
andrewboyson 13:9cd54f7db57a 19 uint16_t qdcount;
andrewboyson 13:9cd54f7db57a 20 uint16_t ancount;
andrewboyson 13:9cd54f7db57a 21 uint16_t nscount;
andrewboyson 13:9cd54f7db57a 22 uint16_t arcount;
andrewboyson 13:9cd54f7db57a 23 };
andrewboyson 13:9cd54f7db57a 24
andrewboyson 13:9cd54f7db57a 25 uint16_t DnsHdrId;
andrewboyson 13:9cd54f7db57a 26
andrewboyson 13:9cd54f7db57a 27 bool DnsHdrIsReply;
andrewboyson 13:9cd54f7db57a 28 bool DnsHdrIsAuthoritative;
andrewboyson 13:9cd54f7db57a 29 bool DnsHdrIsRecursiveQuery;
andrewboyson 13:9cd54f7db57a 30
andrewboyson 13:9cd54f7db57a 31 uint16_t DnsHdrQdcount;
andrewboyson 13:9cd54f7db57a 32 uint16_t DnsHdrAncount;
andrewboyson 13:9cd54f7db57a 33 uint16_t DnsHdrNscount;
andrewboyson 13:9cd54f7db57a 34 uint16_t DnsHdrArcount;
andrewboyson 13:9cd54f7db57a 35
andrewboyson 13:9cd54f7db57a 36 char* DnsHdrPacket;
andrewboyson 13:9cd54f7db57a 37 char* DnsHdrData;
andrewboyson 13:9cd54f7db57a 38
andrewboyson 13:9cd54f7db57a 39 void DnsHdrSetup(void* pPacket)
andrewboyson 13:9cd54f7db57a 40 {
andrewboyson 13:9cd54f7db57a 41 DnsHdrPacket = (char*)pPacket;
andrewboyson 13:9cd54f7db57a 42 DnsHdrData = DnsHdrPacket + HEADER_LENGTH;
andrewboyson 13:9cd54f7db57a 43 }
andrewboyson 13:9cd54f7db57a 44
andrewboyson 13:9cd54f7db57a 45 void DnsHdrRead()
andrewboyson 13:9cd54f7db57a 46 {
andrewboyson 13:9cd54f7db57a 47 struct header* pHeader = (header*)DnsHdrPacket;
andrewboyson 13:9cd54f7db57a 48
andrewboyson 13:9cd54f7db57a 49 DnsHdrId = NetToHost16(pHeader->id);
andrewboyson 13:9cd54f7db57a 50
andrewboyson 13:9cd54f7db57a 51 uint8_t uflags = pHeader->uflags;
andrewboyson 13:9cd54f7db57a 52 DnsHdrIsReply = uflags & 0x80;
andrewboyson 13:9cd54f7db57a 53 DnsHdrIsAuthoritative = uflags & 0x04;
andrewboyson 33:714a0345e59b 54 DnsHdrIsRecursiveQuery = uflags & 0x01;
andrewboyson 13:9cd54f7db57a 55
andrewboyson 13:9cd54f7db57a 56 DnsHdrQdcount = NetToHost16(pHeader->qdcount);
andrewboyson 13:9cd54f7db57a 57 DnsHdrAncount = NetToHost16(pHeader->ancount);
andrewboyson 13:9cd54f7db57a 58 DnsHdrNscount = NetToHost16(pHeader->nscount);
andrewboyson 13:9cd54f7db57a 59 DnsHdrArcount = NetToHost16(pHeader->arcount);
andrewboyson 13:9cd54f7db57a 60
andrewboyson 13:9cd54f7db57a 61 }
andrewboyson 13:9cd54f7db57a 62 void DnsHdrWrite()
andrewboyson 13:9cd54f7db57a 63 {
andrewboyson 13:9cd54f7db57a 64 struct header* pHeader = (header*)DnsHdrPacket;
andrewboyson 13:9cd54f7db57a 65
andrewboyson 13:9cd54f7db57a 66 pHeader->id = NetToHost16(DnsHdrId);
andrewboyson 13:9cd54f7db57a 67
andrewboyson 13:9cd54f7db57a 68 uint8_t uflags = 0;
andrewboyson 13:9cd54f7db57a 69 uint8_t lflags = 0;
andrewboyson 13:9cd54f7db57a 70 if (DnsHdrIsReply) uflags |= 0x80;
andrewboyson 13:9cd54f7db57a 71 if (DnsHdrIsAuthoritative) uflags |= 0x04;
andrewboyson 13:9cd54f7db57a 72 if (DnsHdrIsRecursiveQuery) uflags |= 0x01;
andrewboyson 13:9cd54f7db57a 73 pHeader->uflags = uflags;
andrewboyson 13:9cd54f7db57a 74 pHeader->lflags = lflags;
andrewboyson 13:9cd54f7db57a 75
andrewboyson 13:9cd54f7db57a 76 pHeader->qdcount = NetToHost16(DnsHdrQdcount);
andrewboyson 13:9cd54f7db57a 77 pHeader->ancount = NetToHost16(DnsHdrAncount);
andrewboyson 13:9cd54f7db57a 78 pHeader->nscount = NetToHost16(DnsHdrNscount);
andrewboyson 13:9cd54f7db57a 79 pHeader->arcount = NetToHost16(DnsHdrArcount);
andrewboyson 13:9cd54f7db57a 80 }
andrewboyson 13:9cd54f7db57a 81 void DnsHdrLog(char* title, int protocol)
andrewboyson 13:9cd54f7db57a 82 {
andrewboyson 14:e75a59c1123d 83 char text[100];
andrewboyson 15:6ca6778168b1 84 DnsProtocolToString(protocol, sizeof(text), text);
andrewboyson 15:6ca6778168b1 85 LogTimeF("%s %s\r\n", text, title);
andrewboyson 14:e75a59c1123d 86 if (EthProtocol == IPV6)
andrewboyson 14:e75a59c1123d 87 {
andrewboyson 35:93c39d260a83 88 Log(" IP: src "); Ip6LogHeaderSrc(); Log(" dst "); Ip6LogHeaderDst(); Log("\r\n");
andrewboyson 14:e75a59c1123d 89 }
andrewboyson 14:e75a59c1123d 90 else if (EthProtocol == IPV4)
andrewboyson 14:e75a59c1123d 91 {
andrewboyson 35:93c39d260a83 92 Log(" IP: src "); Ip4LogHeaderSrc(); Log(" dst "); Ip4LogHeaderDst(); Log("\r\n");
andrewboyson 14:e75a59c1123d 93 }
andrewboyson 14:e75a59c1123d 94 else
andrewboyson 14:e75a59c1123d 95 {
andrewboyson 14:e75a59c1123d 96 LogF(" Unknown eth protocol %04hX\r\n", EthProtocol);
andrewboyson 14:e75a59c1123d 97 }
andrewboyson 15:6ca6778168b1 98 LogF(" Port: src %5hu; dst %5hu\r\n", UdpSrcPort, UdpDstPort);
andrewboyson 13:9cd54f7db57a 99 LogF(" Ident %hd\r\n", DnsHdrId);
andrewboyson 15:6ca6778168b1 100 if (DnsHdrIsReply)
andrewboyson 15:6ca6778168b1 101 {
andrewboyson 15:6ca6778168b1 102 if (DnsHdrIsAuthoritative) LogF(" Authoritative reply\r\n");
andrewboyson 15:6ca6778168b1 103 else LogF(" Non authoritative reply\r\n");
andrewboyson 15:6ca6778168b1 104 }
andrewboyson 15:6ca6778168b1 105 else
andrewboyson 15:6ca6778168b1 106 {
andrewboyson 15:6ca6778168b1 107 if (DnsHdrIsRecursiveQuery) LogF(" Recursive query\r\n");
andrewboyson 15:6ca6778168b1 108 else LogF(" Non recursive query\r\n");
andrewboyson 15:6ca6778168b1 109 }
andrewboyson 14:e75a59c1123d 110 LogF(" qd, an, ns, ar %hu, %hu, %hu, %hu\r\n", DnsHdrQdcount, DnsHdrAncount, DnsHdrNscount, DnsHdrArcount);
andrewboyson 13:9cd54f7db57a 111 }
andrewboyson 13:9cd54f7db57a 112